Verbotene Reaktionen
- Prohibited reactions according to the Woodward-Hoffmann rules were examined. For bicyclo[2.2.0]hex-1(4)-ene (18), the heat of hydrogenation was measured to be \(\Delta\)H\(_f\) = -102.0 kcal/mol, resulting in an enthalpy of formation of \(\Delta\)H\(_f\) = 72.5 kcal/mol. Ring opening to 1,2-dimethylenecyclobutane from 60 to 100°C in the gas phase gave the activation enthalpy \(\Delta\)Hǂ = 26.16 kcal/mol. The reaction of 18 with butadiene, cyclopentadiene, and pyridazine afforded propellanes. These and the hydrogenation products were thermolyzed and the activation parameters were determined. The propellanes can escape the antiaromatic transition state by twisting. For the [3.2.1]propellane, the activation parameters of the ring opening to 1,3-dimethylenecyclohexane were determined as \(\Delta\)Hǂ = 50.46 kcal/mol. Here, the forbidden antiaromatic state is largely realized. The activation parameters of the Boot-Cope rearrangement of trans-2,3-dimethyl-d\(\_4\)-dimethylenecyclohexane were determined and a diradical transition state derived.
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| Author: | Norbert KonradtGND |
|---|---|
| URN: | urn:nbn:de:hbz:294-93950 |
| DOI: | https://doi.org/10.13154/294-9395 |
| Referee: | Wolfgang RothGND, Dieter HasselmannGND |
| Document Type: | Doctoral Thesis |
| Language: | German |
| Date of Publication (online): | 2022/11/02 |
| Date of first Publication: | 2022/11/02 |
| Publishing Institution: | Ruhr-Universität Bochum, Universitätsbibliothek |
| Granting Institution: | Ruhr-Universität Bochum, Fakultät für Chemie und Biochemie |
| Date of final exam: | 1990/06/22 |
| Creating Corporation: | Fakultät für Chemie und Biochemie |
| GND-Keyword: | Verbotene Reaktion; Woodward-Hoffmann-Regel; Cycloeliminierung; Propellane; Bildungsenthalpie |
| Institutes/Facilities: | Lehrstuhl für Organische Chemie I |
| Dewey Decimal Classification: | Naturwissenschaften und Mathematik / Chemie, Kristallographie, Mineralogie |
| faculties: | Fakultät für Chemie und Biochemie |
| Licence (German): |  Keine Creative Commons Lizenz - es gelten der Veröffentlichungsvertrag und das deutsche Urheberrecht |
